RAIL services on the London Waterloo to Alton line are expected to be severely disrupted this evening because of “significant” leaf fall".

South West Trains has already cancelled a number of services across its network tonight (Thursday), including the 6.05pm service from Waterloo to Farnham.

A statement on the operator’s website reads: “Over the past few days many rail services across the UK have been impacted by the current autumnal conditions, affecting the track that our trains run on.

“Following information from our forecasters and advice from Network Rail, we have prepared for today’s track conditions, which are expected to be particularly challenging.

“Therefore, to avoid significant congestion affecting a large part of the network this evening, a very small number of our services have been cancelled or amended.

“Due to the alterations, we are expecting services to be busier than normal this evening.”

South West Trains’ network passes through many forested and densely-vegetated areas and can be affected by leaf mulch forming on the railway lines.

When leaves fall on or near the tracks they are swept up and compressed under the wheels of passing trains. Without being cleared, this accumulates with each passing train.

This high pressure crushing of the leaves creates the equivalent of a ‘Teflon’ non-stick coating on the rails which presents a major risk as the trains can simply slide along the rails when they try to stop, similar to black ice on roads.

South West Trains says it is “working hard” within the South West Trains-Network Rail Alliance to ensure the effects of ‘leaves on the line’ are reduced to a minimum.

This includes cutting back problem trees and using specialist equipment to remove the leaf coating from the tracks - both of which can result in delays.